The invention relates generally to swinging and folding door pivot devices, and, more particularly, to lower pivot assemblies having structures that exhibit improved tolerance to lateral forces. The invention further relates to a method of using such pivot devices.
Swinging and folding doors are commonly mounted adjacent to a door jamb by way of pivots at the top and bottom. In general, pivot structures utilize an upper pivot assembly mounted on an upper track and a lower pivot assembly mounted to the floor. Commonly, the lower pivot assembly provides both vertical and horizontal adjustment for alignment of the door within the door jamb. A variety of differing approaches exist to implement the lower pivot assembly. In one variant, the lower pivot assembly comprises an interlocking pivot pin and jamb bracket. In another variant, a pivot block is placed between the pivot pin and the jamb bracket.
Generally it is desirable for the lower pivot assembly to resist a variety of lateral forces exerted on the door. Greater resistance to lateral forces ensures against slippage of the pivot pin or pivot block within the jamb bracket and deters misalignment or disconnection of the pivot assembly. It is also desirable to provide convenient vertical and horizontal adjustments. The ability to adjust vertical door height allows modifications for carpet thickness and differing door frame sizes. The ability to make horizontal adjustments allows alignment of the door within the door frame.
For example, U.S. Pat. No. 3,866,658 describes a lower pivot assembly for a door which permits both vertical and horizontal adjustments. However, adjustments are somewhat difficult and require the use of tools. Adjustment of the door height is provided by a threaded pin and an adjustment nut that, upon rotation of the pin by a wrench, adjusts vertical height. To adjust the pivot block horizontally, the pivot block must be removed from the jamb bracket. The pivot block is then reinserted at a new horizontal position. Therefore, such an arrangement calls for use of a wrench to adjust the vertical door height and removal of the pivot block to adjust the horizontal pivot position.
In U.S. Pat. No. 4,106,158, the pivot pin has teeth thereon which engage complementary teeth on the jamb bracket. Both vertical and horizontal positioning are controlled by altering the pivot pin. Vertical adjustment is achieved by rotating the pivot pin. Horizontal adjustment is achieved by lifting the pin out of the jamb bracket and reinserting it at a desired location. In the preferred form, the teeth are tapered downwardly and inwardly such that they can disengage during the normal operation of the door. More specifically, if something is blocking the door when attempting to close it, the lateral force generated can cause the pivot pin and the door to move upwardly. Such an upward movement may separate the pivot pin from the jamb bracket. As a result, the pin and the door may move horizontally out of alignment.
Thus, a need exists for a vertically and laterally adjustable lower pivot assembly that prevents undesired lateral movement of the assembly.